Turbo-electric propulsion of vessels.



E..THOMSON. TURBO-ELECTRIC PROPULSION OP VBSSELS. APPLICATION FILED JAN.16. 1911.

1,047358, Patented Dec.17,1912.

'2 fit-mature 'Wibnesses: Invenbor:

Mp Elihu Thcbmsor'l, :ze4- a. Elm/M52264;

ELIHU THOMSON, OF SWAMPSCOTT, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

-TURBO-ELECTRIC PROPULSION 0F VESSELS.

To all whom it may concern:

Be it 'known that I, ELIHU THOMSON, a citizen of the United States, residing at Swampscott, county of Essex, State of Massachusetts, have invented certain new and useful Improvements in Turbo-Electric Propulsion of Vessels, of which the following is a specification.

This invention relates to the propulsion of ships by means of electric motors supplied with currentfromturboenerator's.

Steam turbines, in order todevelop the best efficiency, should run at high speed, and therefore theycannot be connected directly to the propelling screws of a ship. By the interposition of electric generators and motors, a satisfactory reduction in speed can be obtained, and ample opportunity is afforded for flexibility of contn'ol in speed, so that cruising, maneuvering, backing and other evolutions can be readily performed. In the presentinvention, however, I have departed from the customary systems of electric drive, and instead of generators and motors, I have provided a species of electric clutch for connecting the turbine shaft to the propeller shaft, said clutch permitting a slip between its revolving parts suflicient to allow the required reduction in speed of rotation between the two shafts. By using a pair of turbines, screws and clutches, and brakes, and providing suitable cross connections, I can effect a great variation in speed, for cruising and.

other purposes.

The accompanying drawing is a diagram of circuits, machinery. and control apparatus embodying my invention.

The steam turbines 1 and 2 are of the high speed, high efiiciency type, and are governed as to speed by'the usual ways of controlling the steam in accordance with the variations in load. Proper throttle valves are provided for shutting down these engines, as usual. On the shaft of the turbine 1, is mounted a field magnet 3 and on the shaft of the turbine 2 the field magnet 4, each'field magnet consisting of a laminated core of iron carrying a distributed winding of insulated copper wire. These windings are supplied with current through slip rings 5 and 6, from a direct current exciter.7, shown diagrammatically and having the usual regulating appliances. Con-.

centric with the field magnet on each shaft Specification of Letters Patent.

Application filed January 16, 1911. Serial No. 602,922.

is a laminated iron structure 12 and 13 provided with induced or armature windings of a polyphase (and preferably a threephase) character. "The terminals of these windings, as-is usual with the rotating members of many electrical machines are carried to slip rings 14 and 15 on the respective shafts on which the armature structures are mounted, said shafts being alined respectively with the turbine shafts. The leads from the brushes of these slip rings run to switches 16 and 17 by means of which the windings can be short circuited when de-- sired. Branch leads enable the two 'machines to be interconnected, and a switch 18 enables two of said leads to be interchanged When desired. On each ofthe shafts carrying the armature structures 12 and 13 is mounted a propelling screw '19 and 20. In the drawing, the .blades of the two screws are shown as inclined in opposite directions, which requires that the two armatures l2 and 13 shall rotate in opposite directions for propelling the ship forward.

-Means are provided for holding from rotation, when the other or both of said turbines' This holding device or devices may consist of a mechanical or'a magnetic brake on clutch, such clutch or clutches being controllable at will to produce the desired effect. In the drawing, electro-magnetic clutches 8 and 9 are shown, taking current from the exciter 7, through suitable regulating devices whereby the current can be varied or cut off. Controlling the circuits of the revolving field magnets 3 and 4 for varying the resistances of said circuit-s to control the strengths of the magnetic fields developed by the windings on said field Ina nets.

The operation is asfoll'ows: Owing to the magnetic drag exerted upon and 4,. the shafts carrying the propelling screws will be carried around with said field magnets, when the short-circuiting switches 16 and 17 are closed and the interconnecting switch 18 is open. Some considerable variation in the speed of the screws can be obtained by varying the strength of thefield magnets so as to alter the slip between each of them and the revoluble armatures 12 and 13 respectively. Further variations can behad by controlling the speed of the turblnes Patented Dec,17, 1912.

desired, the shaft of one or devices 10 and 11 are shown in v the armature structures by the revolving field magnets .3 w

l stationary. This will cause the latter arma- 7 tion of one ofthe screws will 'be reversed;

the one whose armature 1s recelvlng' land 2, which drive 'When, however, it is desired to effect a confield' magnet.

the fields 3 and 4.

siderable reduction in the speed of the vessel, then one or the other of the turbines has its steam shut oif, and the correspondnng,v

clutch 8, or-9, as the case may be, is set 1nto action to hold stationary both the shaft of the turbine and the field magnet carried thereby. Under these conditions, the shortcircuiting switches 16 and 17 are opened, and the switch 18 is closed, ,so that the three-phase current generated in the windings of the armature whose field magnet is still rotating will be delivered to' the windings of the armature whose field magnet-is ture to rotate around its stationary field magnet, but under these conditions the speed of rotation is reduced to approximately onehalf the speedy developed when both turbines are in operation. This low speed is suitable for crulsing or maneuvering. Upon interchanging the connections of two of the interconnecting leads, by suitably manipulating the switch 18, the direction of rotathat is, current from the armature of the rotating Both screws cannot be' re,- versed at the same time,

- of backing the ship, a; small auxiliary screw,

-' combination with a. -pair of "driven byja small steam engine, can be provided, or a set of-jrevers'ing bucket. wheels c'anbe incorporated in the turbines land 2. The various switches can be conveniently operated-bye system some central" station, as will be'ireadily understood'bythe skilled engineer.

Inaccordance with the provisions" of'the patent statutes,

ciple of operation; of my invention, to- I the. apparatus which Ifnow.

consider-to represent thev best embodiment desire to have it understood thattheapparatus shown is only illustra-- tive, and that the invention can be carrie out'by otherm'eans." a l Whatl claim as'n'ew byLetters 5.5 0

gether with thereof, but I 1. Inc. ,system of ship pro ulsion, .the

tur 'ines, of re- .volvi greldmagnets eachi drivenjby its but forthe purpose of remote control from gIhave described the prin-\ and desire to'secure Patent 'o'f -th'e United" States, is,'

respective turbine, a revoluble armature structure concentric with each field magnet,

a screw propeller havmg a shaft carrying supplying an exciting current to the windings of the field magnets, circuiting the winding on each armature, conductors connecting the windings, and means for arresting the rotation of at least one of the field magnets.

2. In a system of 'hip propulsion, the combination with a pair of turbines, of revolvingv field magnets each driven by its respective turbine, ,a revoluble armature structure concentric with each field magnet, screw propellerseach having a shaft carrying its respective armature structure, citer supplying current to said field magnet windings, polyphase windings on said armatures, means for interconnecting the same, and means for holding stationary either ofsaid revolving field magnets.

3. In a system of ship propulsion, the combination with a pair of turbines, of revolving field magnets each driven by its respective turbine, an electro-magnetic clutch for holding each field magnet stationary, an exclter supplying current to said armature structures concentric with each of windings, -means for short-circuiting said windings, and means for interconnecting them --and.'-also for interchanging phases when desired, and screw propellers having shafts carrying said armature structures.

4. In a system o-f-ship propulsion, the combination of a plurality of prime movers, shafts. driven thereby, a propeller shaft in line with each-of the said shafts, a field magnet carried by one of the alined shafts, -anarmature carried by the other shaft, means for arresting the rotation of one shaft and thegenerator member carried by it, current collecting devices for the generators, and conductors connecting said devices.

' In witness whereof, I have hereunto set my hand this tenth day of January, 1911.

1 I ELIHU THOMSON.

.1 ,Witnesses:

means for short an exits respective armature structure, means for w field magnets and to said clutches, revoluble said-field magnets and having polyphase 

